Method and cleaning device for cleaning items to be cleaned

ABSTRACT

A method for cleaning items to be cleaned is disclosed. A cleaning device is used that has at least one cleaning chamber and at least one applicator for applying at least one cleaning fluid to the items to be cleaned in the cleaning chamber. A desired hygiene value is prespecified. The method further includes time-resolved recording of at least two influencing variables which influence hygienization of the items to be cleaned. Hygiene share values are determined from the influencing variables using a prespecified relationship between each influencing variable and the respective hygiene value share of said influencing variable. An expected actual hygiene value at the end of the cleaning from the hygiene value shares is ascertained and compared with the desired hygiene value. At least one of the influencing variables is changed based on the comparison. An inventive cleaning device is also disclosed.

RELATED APPLICATIONS

This application is a continuation of PCT/EP2017/079020, filed Nov. 13,2017, which claims priority to DE 10 2016 222 308.9, filed Nov. 14,2016, the entire disclosures of which are incorporated herein byreference in their entirety.

BACKGROUND

This disclosure relates to a method and a cleaning device for cleaningitems to be cleaned, in particular for use in commercial dishwashingand/or in large-scale kitchens. Cleaning devices of said kind can beused, for example, in facilities for mass catering, such as, inparticular, office canteens, canteens in schools, public authorities,hospitals or care facilities. The cleaning device can be used, inparticular, for cleaning items to be cleaned in the form of washwarewhich are used directly or indirectly for preparing, storing or servingfood and drinks. Said items to be cleaned may be, in particular, dishesand/or trays. Other fields of use of this disclosure are also feasiblein principle, in particular fields of use with, in principle, anydesired washware.

A large number of cleaning devices, also called cleaning appliances,which can clean and/or disinfect items to be cleaned are known from theprior art. In the text which follows, without restricting other possiblefields of use, this disclosure makes reference largely to the field ofcommercial washing, for example commercial dishwashing. Therefore, inaddition to automatic programmed washers with static washing processes,conveyor washers or pass-through washers in which the items to becleaned are transported through one or more cleaning chambers by meansof a transportation device are known for example. The design of thesecleaning devices depends overall to a great extent on the variousboundary conditions, such as the type of items to be cleaned, thedegrees of soiling, the throughput or similar conditions for example. Byway of example, reference can be made to cleaning devices which aredescribed, for example, in DE 10 2004 056 052 A1, in DE 10 2007 025 263A1 or in DE 10 2013 220 035 A1.

In contrast to domestic dishwashing, commercial washers generally have aplurality of fluid tanks in order to be able to accelerate a throughputof items to be cleaned. For example, in addition to the actual washtank, a rinse tank is provided, in which rinse tank the temperature of arinse or final rinse fluid can be adjusted as early as while the mainwashing process is still running. Conveyor washers generally have alarge number of cleaning zones in which the items to be cleaned aresequentially cleaned. However, this increase in throughput is generallyassociated with a considerable increase in expenditure of energy and inmany cases also an increase in a requirement for detergent solution incomparison with domestic dishwashing. A generally desirable reduction inthe energy requirement and in the requirement for detergent solution orgenerally for surfactants or other chemical additives must however notbe carried out at the expense of a cleaning result and in particular thehygiene effect achieved. Therefore, various hygiene standards forcommercial washing are provided, such as DIN 10510 in Germany or theso-called NSF3 standard in the USA for example. The latter stipulates,for example, that specific temperatures and concentrations ofdisinfectants have to be maintained in the final rinse operation andthat a warning has to be output in the event of deviations.

EP 2 053 959 B1 describes a method for assessing and ensuring thethermal hygiene effect in a multi-tank washer. The temperature within atleast one treatment zone is transmitted to a machine controller by meansof at least one temperature sensor. On the basis of the temperature, aheat input onto the washware is ascertained and this heat input iscompared with a prespecified heat input. The transportation speed isvaried in order to control the actual heat input.

DE 10 2006 014 464 B3 discloses a device for cleaning dishes, whichdevice has a transportation device for the items to be cleaned. Saidtransportation device can transport the items to be cleaned through atleast one cleaning chamber at different transportation speeds.Furthermore, a metering device for detergent is provided, which meteringdevice dispenses a specific quantity of detergent into the cleaningchamber. The metering device selects the quantity of detergent to bedispensed depending on the transportation speed.

DE 10 2006 019 546 A1 describes a metering device for a batch washerwith a dispensing unit and a controller for the quantity of detergentwhich is to be dispensed, which controller actuates the dispensing unit.The metering device has a control unit which interrupts and/or chokes orintensifies actuation of the dispensing unit by the controller forspecific time intervals.

EP 1 886 615 B1 describes a dishwasher which is designed such thatdinnerware is washed with wash water. The wash water is contained in awash water tank and is collected in the wash water tank after thewashing operation. A portion of the wash water which is contained in thewash water tank is replaced by supplied water after each wash cycle. Thedishwasher furthermore has a detergent supply device which supplies adetergent to the wash water and which increases a supplied quantity ofthe detergent on the basis of the number of wash cycles.

DE 10 2013 203 933 A1 discloses a method for cleaning items to becleaned, in which method at least one rinse liquid is applied to theitems to be cleaned. In this case, supply of at least one component ofthe rinse liquid is increased from a starting value to an equilibriumvalue as the cleaning duration increases.

DE 10 2014 102 970 A1 describes a conveyor washer for washing washware.At least one final rinse zone with at least one final rinse nozzle forspraying final rinse liquid onto the washware and one metering device,which is associated with the final rinse zone, for adding a disinfectantto the final rinse liquid in a metered manner are provided in saidconveyor washer. Furthermore, a sensor device is provided, which sensordevice is designed to detect the concentration of disinfectant in thefinal rinse liquid which is sprayed in the final rinse zone. A controldevice is further provided, which control device is designed to comparethe value for the concentration of disinfectant, which value is detectedby the sensor device, with predefinable concentration values and, in thecase of excessively high deviations in the concentration of disinfectantfrom the predefinable concentration values, to interrupt the washingprocess or to output a warning signal to an operator.

DE 10 2009 024 569 A1 describes a method for operating a conveyorwasher. The conveyor washer has at least one pre-rinse zone with apre-rinse nozzle for spraying pre-rinse liquid onto the washware and atleast one final rinse zone with at least one final rinse nozzle forspraying final rinse liquid onto the washware. At least a portion of thesprayed final rinse liquid is reused as pre-rinse liquid. A meteringdevice which is associated with the final rinse zone is provided foradding a disinfectant to the final rinse liquid in a metered manner.Furthermore, a metering device which is associated with the pre-rinsezone is additionally provided for adding a disinfectant to the pre-rinseliquid in a metered manner. A sensor device is further provided, whichsensor device is designed for detecting the concentration ofdisinfectant in the pre-rinse liquid which is sprayed in the pre-rinsezone. A control device is further provided, which control device isdesigned to actuate one of the metering devices in such a way thatdisinfectant is added in a metered manner depending on the concentrationof disinfectant which is detected by the sensor device.

DE 10 2011 007 507 A1 describes a conveyor washer with at least one washzone and at least one final rinse zone and also with a transportationdevice for transporting washware through the at least one wash zone andthe at least one final rinse zone. In order to reduce the consumption ofdisinfection chemicals and energy but to nevertheless maintain anoptimum final rinse result, it is proposed according to this documentthat the final rinse liquid which is sprayed in the final rinse zonecontains disinfection chemicals which are added in a metered manner, andthat at least one additional final rinse zone which is connecteddownstream of the final rinse zone is provided for spraying fresh waterwithout disinfection chemicals onto the washware to be treated. The atleast one additional final rinse zone has an associated collectingdevice for collecting liquid which is sprayed in the additional finalrinse zone. A liquid transfer system is further provided, by means ofwhich liquid transfer system the liquid collected in the collectingdevice can be supplied directly to the wash zone.

DE 10 2012 213 271 A1 describes a washer which is embodied in the formof a conveyor washer or in the form of a batch washer and has at leastone wash system for spraying wash liquid in a wash zone or during awashing phase and at least one final rinse system for spraying finalrinse liquid in a final rinse zone or during a final rinse phase,wherein a control device is further provided for actuating the at leastone wash system and/or the at least one final rinse system in accordancewith a predefined sequence program. In order to be able to saveresources during operation of the washer, wherein the requirements inrespect of the hygienic operation of the washer defined in therespectively locally applicable hygiene guidelines (hygiene guidelinesapplicable within territorial limits) are simultaneously met, it isprovided according to this document that at least one first sequenceprogram is stored in the control device, which first sequence programhas been created taking into account requirements in respect of hygienicoperation of a commercial washer which are applicable in a firstterritorial region, and that at least one second sequence program isstored in the control device, which second sequence program has beencreated taking into account requirements in respect of hygienicoperation of a commercial washer which are applicable in a secondterritorial region.

DE 10 2008 024 543 A1 describes a method for operating a washer. In thiscase, a wash pump is actuated during a wash process in such a way that awash liquid of at least one wash nozzle is at least temporarily suppliedvia the line system. Furthermore, a profile of a hydrostatic pressure ofthe wash liquid in a line system is recorded and compared with aprespecified pressure profile. If the recorded pressure profile differsfrom the prespecified pressure profile, an automatic control action istaken in the washing process, a fault message is output by means of anoptical and/or acoustic interface of the washer or a message is outputto a remote servicing point by means of a remote control interface ofthe washer, depending on the size and the time gradient of a differencebetween the prespecified pressure profile and the recorded pressureprofile.

WO 2011/062790 A2 discloses a washing device in which a sensor and acontrol device for detecting a volumetric flow rate of a liquid in apipe system and for comparing a profile of said volumetric flow ratewith a profile of a prespecified flow rate are provided. The controldevice is designed to intervene with automatic control or to output awarning in the event of a deviation.

These known methods and cleaning devices with thermal/chemical methodsdescribe measuring and varying the temperature in order to achieve adesired hygiene effect and to maintain hygiene standards. Methods andcleaning devices of this kind do not allow accurate control andmonitoring of the hygiene effect. In addition, adequate hygienereliability can be achieved only with the use of a large amount of theresources energy and chemical additives, and this leads to a high levelof expenditure for the operator and is disadvantageous for theenvironment.

SUMMARY

This disclosure teaches a method and a cleaning device which at leastlargely avoid the disadvantages of known methods and cleaning devicesand improves hygiene reliability while using a low level of resources.

In the text which follows, the terms “have,” “encompass,” “comprise” or“include” or any grammatical departures therefrom are usednon-exclusively. Accordingly, these terms can refer either to situationsin which, besides the features introduced by these terms, no furtherfeatures are present, or to situations in which one or more furtherfeatures are present. For example, the expression “A has B,” “Aencompasses B,” “A comprises B” or “A includes B” can refer either tothe situation in which, apart from B, no further element is present in A(i.e., to a situation in which A exclusively consists of B), or to thesituation in which, in addition to B, one or more further elements arepresent in A, for example element C, elements C and D or even furtherelements.

Furthermore, it should be noted that the terms “at least one” and “oneor more” and grammatical modifications of these terms, if they are usedin association with one or more elements or features and are intended toexpress the fact that the element or feature can be provided singularlyor multiply, generally are used only once, for example when the featureor element is introduced for the first time. When the feature or elementis subsequently mentioned again, the corresponding term “at least one”or “one or more” is generally no longer used, without restricting thepossibility that the feature or element can be provided singularly ormultiply. In the same connection, it shall be understood for purposes ofthis disclosure and appended claims that, regardless of whether thephrases “one or more” or “at least one” precede an element or featureappearing in this disclosure or claims, such element or feature shallnot receive a singular interpretation unless it is made explicit herein.By way of non-limiting example, the terms “cleaning chamber,”“influencing variable” and “hygiene value share,” to name just a few,should be interpreted wherever they appear in this disclosure and claimsto mean “at least one” or “one or more” regardless of whether they areintroduced with the expressions “at least one” or “one or more.” Allother terms used herein should be similarly interpreted unless it ismade explicit that a singular interpretation is intended.

Furthermore, in the text which follows, the terms “preferably,” “inparticular,” “for example” or similar terms are used in conjunction withoptional features, without alternative embodiments being restrictedthereby. In this regard, features which are introduced by these termsare optional features, and the scope of protection of the claims, and inparticular of the independent claims, is not intended to be restrictedby these features. In this regard, the invention, as will be recognizedby the person skilled in the art, can also be carried out using otherconfigurations. In a similar way, features which are introduced by “inone embodiment of the invention” or by “in one exemplary embodiment ofthe invention” are understood as optional features, without alternativeconfigurations or the scope of protection of the independent claimsbeing intended to be restricted thereby. Furthermore, all possibilitiesof combining the features introduced by these introductory expressionswith other features, be they optional or non-optional features, areintended to remain unaffected by these introductory expressions.

A first aspect of this disclosure proposes a method for cleaning itemsto be cleaned. Here, items to be cleaned can be understood to mean, ingeneral, any items which can be subjected to cleaning or a cleaningmethod. Without restricting other possible refinements, reference ismade below to items to be cleaned in the form of washware. Here,washware is intended to comprise any objects which are used to prepare,serve or store food and drinks. Examples which can be mentioned hereinclude crockery such as cups, plates, glasses, dishes or bowls.Furthermore, pots, trays, cutlery, warming devices or similar devicescan be mentioned. However, it should be expressly noted that other typesof items to be cleaned can also be cleaned, such as industrial piecegoods, bulk goods, containers or other types of items to be cleaned forexample.

Cleaning can be understood to mean both removing adhering soiling orother impurities from the items to be cleaned and also a germ-reducingand/or germ-killing effect or even disinfecting effect. Hygienization isunderstood to mean, in principle, both removal of germs, in particular agerm-reducing and/or germ-killing or even disinfecting effect, and alsoremoval of substances such as chemicals, for example residues ofadditives of the at least one cleaning fluid.

A cleaning device having at least one cleaning chamber and at least oneapplication device (also referred to herein as “applicator”) forapplying at least one cleaning fluid to the items to be cleaned in thecleaning chamber is used in the method. Within the scope of thisdisclosure, a cleaning device is intended to be understood to mean, ingeneral, a device which is configured to at least partially removeadhering impurities and/or germs from items to be cleaned. The cleaningdevice can be, for example, a dishwasher, in particular a commercialdishwasher, for example an automatic programmed dishwasher and/or apass-through dishwasher. However, as an alternative or in addition, thecleaning device can also be entirely or partially configured as acleaning and disinfection appliance, for example as a cleaning devicewhich is configured to clean containers for receiving human excreta. Ingeneral, reference can be made in this respect to the cleaning devicesdescribed in DE 10 2004 056 052 A1 and/or in DE 10 2007 025 263 A1. Thecleaning device can also be a washer as can be used for cleaningcontainers in the field of food production and/or food-processing.Furthermore, the cleaning device may be a disinfection washer, forexample a washer for cleaning and disinfecting breathing masks. However,other refinements are also conceivable in principle.

The cleaning device can be configured, in particular, as a conveyorwasher, in particular as a pass-through dishwasher. Here, a conveyordishwasher is intended to be understood to mean a dishwasher, that is tosay a machine for cleaning washware in the form of dishes which isconfigured to transport the washware through a cleaning chamber. Inparticular, said conveyor dishwasher may be a flight-type dishwasherand/or a rack conveyor dishwasher, that is to say a dishwasher in whichthe crockery is transported through the cleaning device by means of aconveyor belt, for example a conveyor belt on which the crockery isplaced directly and/or on which one or more racks carrying the crockeryto be cleaned are placed. The conveyor dishwasher can be configured, inparticular, for commercial use, for example in one or more of theabovementioned facilities for mass catering. However, other types ofcleaning devices are also possible in principle.

The cleaning fluid can be, for example, a cleaning liquid and/or agaseous cleaning fluid. For example, this cleaning fluid can comprise acleaning liquid, for example an aqueous cleaning liquid, for examplewater in the form of fresh water and/or with one or more additives, forexample with one or more detergent concentrates and/or one or more finalrinse aid concentrates and/or one or more disinfectants. For example,the cleaning fluid can have one additive or a plurality of additives,for example at least one additive selected from the group consisting ofa detergent concentrate, a final rinse aid and a disinfectant. As analternative or in addition, the cleaning fluid can comprise, forexample, steam. However, other refinements are also conceivable inprinciple. The at least one cleaning fluid can comprise, in principle,at least one cleaning liquid for example, in particular at least oneaqueous cleaning liquid. Other types of cleaning fluids can also be usedin principle. A cleaning fluid can therefore be understood to mean anydesired fluid, in particular a liquid, which can have a cleaning effecton the items to be cleaned.

Here, a cleaning chamber is understood to mean, in general, a chamber inwhich the above-described cleaning process for the items to be cleanedis completely or partially carried out. In particular, the cleaningfluid or one of several cleaning fluids is/are applied in a cleaningchamber. Furthermore, the cleaning device can comprise at least onetransportation device (also referred to herein as a “transporter”) whichis configured to transport the items to be cleaned in a transportationdirection from an inlet region, through the cleaning chamber, to anoutlet region. The chamber is preferably completely or partiallyenclosed by a housing. In particular, the cleaning chamber can be oftunnel-like design or comprise a portion of a tunnel, for example withan inlet and an outlet, wherein the items to be cleaned are insertedinto the cleaning chamber at the inlet and exit from the cleaningchamber at the outlet. An inlet is therefore intended to be understoodto mean a region outside the cleaning chamber which is arranged directlyin front of the cleaning chamber in the transportation direction and inwhich the items to be cleaned can be placed on the transportationdevice. Accordingly, an outlet is intended to be understood to mean aregion outside the cleaning chamber which is arranged directly behindthe cleaning chamber in the transportation direction and in which theitems to be cleaned can be removed from the transportation device.Within the scope of this disclosure, a transportation device ortransporter is intended to be understood to mean, in general, anydesired device which is configured to transport the items to be cleanedthrough the cleaning chamber in the transportation direction. Forexample, this transportation device can be selected from amongst a beltconveyor device with at least one conveyor belt, a latch transportationsystem and a roller transportation device having at least onetransportation roller or a plurality of transportation rollers, forexample one or more driven transportation rollers by means of which, forexample, the items to be cleaned can be transported directly and/or oneor more racks which hold the items to be cleaned can be transportedthrough the cleaning chamber in the transportation direction. Thetransportation device can have, for example, at least one drive, forexample at least one drive motor. For example, said drive can be a drivewhich drives at least one conveyor belt and/or at least onetransportation roller or another type of transportation element of thetransportation device.

Here, an application device or applicator is intended to be understoodto mean, in principle, any desired device or combination of devices bymeans of which the cleaning fluid can be applied to the items to becleaned, for example by spraying, irradiating or dripping the cleaningfluid onto the items to be cleaned. For example, the application devicecan have at least one nozzle system. Therefore, for example, one or morenozzle systems can be provided in the conveyor dishwasher. If aplurality of cleaning zones are provided for example, each cleaning zonecan have for example at least one associated nozzle system of this kind.For example, the cleaning device can be configured in such a way thatthe items to be cleaned pass the cleaning zones one after the other. Forexample, reference can be made to the abovementioned prior art for anarrangement of cleaning zones of this kind.

The method comprises the following steps:

-   a. prespecifying a desired hygiene value which is to be achieved    with the cleaning;-   b. time-resolved recording of at least two influencing variables    which have an influence on a hygienization of the items to be    cleaned;-   c. determining hygiene value shares from the influencing variables    using a prespecified relationship between each influencing variable    and the respective hygiene value share of said influencing variable;-   d. ascertaining an expected actual hygiene value at the end of the    cleaning from the hygiene value shares;-   e. comparing the expected actual hygiene value with the desired    hygiene value; and-   f. influencing at least one influencing variable depending on the    result of the comparison.

The method steps can be carried out in said order or else in anotherorder. Furthermore, one or more of said method steps can also be carriedout in parallel with respect to time, with an overlap with respect totime or else at the same time. Furthermore, one or more of the methodsteps can be repeatedly or permanently carried out individually or ingroups.

A hygiene value is intended to be understood to mean, in general, avariable which quantifies a hygiene result. For example, the hygienevalue can be a hygiene level. For example, the hygiene value can beselected from A0 values or H.U.E. values; a measure of a reduction in apopulation of a target germ. A0 values and H.U.E. values are a measureof the reduction, or mortality rate, of a target germ due to a thermalaction. The higher the acting temperature, the greater the germ-reducingeffect per unit time. For example, more A0 values and H.U.E. values persecond can be reached at a relatively high temperature. However,operation of the cleaning device at low temperatures may be desirable,for example for reducing use of resources such as energy for heating.The reduction in the target germ can be influenced by further variables,such as the influencing variables, mechanics and chemistry for example,in particular by a concentration or composition of at least one additiveof the cleaning fluid. An SUE value (sanitation unit equivalent) persecond can be a measure of the reduction in the target germ, whichmeasure takes into account a dependency on the temperature and thedetergent chemicals used, where

SUE/sec=Ae ^(BT),

where A=1/7000000 and B=0.191. Here, a SUE value of 100 corresponds to a5 log-level reduction in the target germ. The parameters A and B areempirical values determined using a population of Staphylococcus aureusas target germ population. The method is not linked to said target germpopulation. For example, the method can be matched to alteredrequirements and other germs can be imagined as target germ, for exampleEnterococcus faecium. The SUE method can allow the concentration orcomposition of the at least one additive of the cleaning fluid on thehygiene effect to be taken into account and thereby allow operation ofthe cleaning device at low temperatures with the hygiene effectremaining the same. The hygiene value can preferably be a SUE value.

Furthermore, in terms of the hygiene value, a distinction can be drawnbetween a desired hygiene value and an actual hygiene value. A desiredhygiene value is intended to be understood to mean a hygiene resultwhich the cleaning device is intended to achieve with the cleaning, inparticular at the end of the cleaning process, for example an end of acleaning program in a single-chamber washer and/or an automaticprogrammed washer and/or, for example, at an end of a tunnel in the caseof a conveyor dishwasher. An actual hygiene value is intended to beunderstood to mean a hygiene result which the cleaning device actuallyachieves.

The desired hygiene value can be selected from the group consisting of:an A0 value which is to be achieved overall with the cleaning accordingto DIN EN ISO 15883; a hygiene level which is to be achieved accordingto DIN 10510, at the desired prespecifications for tank and boilertemperatures according to DIN 10510; a number of HUE units according tothe NSF3 standard which are to be achieved overall with the cleaning; areduction in a population of a target germ which is to be achievedoverall with the cleaning, in particular a reduction in the populationof Staphylococcus aureus which is to be achieved overall with thecleaning. The desired hygiene value can correspond to 99.999% death of apopulation of Staphylococcus aureus. In particular, the desired hygienevalue can be a SUE value. Prespecification of a desired hygiene valuewhich is to be achieved with the cleaning can be understood to meanproviding a desired hygiene value. For example, the prespecification cancomprise selecting a desired hygiene value, for example from a list,and/or entering a desired hygiene value, for example into a man/machineinterface of the cleaning device, in particular a controller of thecleaning device.

Within the scope of this disclosure, an influencing variable is intendedto be understood to mean, in general, a quantifiable variable which caninfluence the operation of the cleaning device and/or a cleaning resultof the cleaning device in some way. The hygienization, also called thehygiene effect, for cleaning sequences can be determined by variousinfluencing variables. The influencing variables can be selected fromthe group consisting of: a duration of the cleaning; at least onetemperature of the at least one cleaning fluid; at least one measurementvariable which is characteristic of a mechanical action of the at leastone cleaning fluid on the items to be cleaned, in particular a pressureand/or a flow rate of the at least one cleaning fluid; at least oneconcentration of at least one disinfectant in the at least one cleaningfluid; at least one concentration of at least one detergent concentratein the at least one cleaning fluid; at least one pH value of the atleast one cleaning fluid; at least one measurement variable which ischaracteristic of an effect of a final rinse operation. The influencingvariables can influence each other. The hygiene effect can be presentedas a pie chart in which the influencing variables represent segments ofa circle which have to add up to form the entire circle. A reduction inone of these influencing variables can respectively be compensated forby increasing one or more of the other influencing variables.

The at least two influencing variables can comprise, as firstinfluencing variable, at least one temperature of the at least onecleaning fluid and furthermore at least one further influencingvariable. Recording an influencing variable is understood to mean, ingeneral, determining and/or detecting and/or measuring the influencingvariable, in particular a measurement value, and/or a measure of theinfluencing variable. Time-resolved recording of the influencingvariable is understood to mean, in general, recording of the influencingvariable over time and/or development of the influencing variable overtime. The time-resolved recording of the at least two influencingvariables can take place at prespecified or prespecifiable times or atprespecified or prespecifiable intervals. In particular, thetime-resolved recording can take place before influencing theinfluencing variable.

For example, the cleaning device can have at least one sensor forrecording the influencing variables. Within the scope of thisdisclosure, a sensor is intended to be understood to mean, in general, adevice which is configured to record one or more measurement values ofthe influencing variables, preferably in the form of one or more ofelectronic measurement values. The measurement values can be of analogand/or digital form. The sensor can comprise, for example, at least onesensor element which is configured to generate at least one sensorsignal, for example an analog or digital sensor signal, in accordancewith the state variables which are to be recorded. However, in additionto the at least one sensor element, the sensor can comprise one or morefurther elements. For example, the sensor can comprise, in particular,one or more supply lines which are connected to the sensor elementand/or other elements of the sensor. Furthermore, for example, at leastone actuating and/or evaluating circuit can be provided, which actuatingand/or evaluating circuit can be connected to the sensor element and isoften also referred to as measurement printed circuit board or simplyonly as printed circuit board. Furthermore, the sensor can comprisefurther elements, such as at least one analog/digital converter (A/Dconverter) and/or at least one signal line and/or data line and/or aninterface for example. The overall assembly, which is made up of the atleast one sensor element and optionally the at least one further elementof the sensor, can together form a sensor system and/or a measurementchain of the sensor, which measurement chain can ultimately be connectedto a controller. The sensor itself can therefore be a sensor system orcan be a constituent part of a sensor system. The measurement chain andthe design of said measurement chain can ultimately determine how adetermined value of the influencing variables and/or a change in thisvalue act on one or more sensor signals which are made available to thecontroller. Therefore, overall, the sensor can comprise at least onesensor element and at least one further element, in particular at leastone further element selected from the group comprising: an actuatingand/or evaluating circuit (in particular for processing at least onemeasurement value or sensor value), an interface, an analog/digitalconverter (A/D converter), a wireless and/or wired transmission element,a signal line and/or data line, a voltage supply, an A/D converter, adisplay element, a data memory, a radio module. However, otherrefinements are also possible.

The basis for carrying out the present method can be correspondingcontrol hardware and/or control software of the cleaning device, whichcontrol hardware and/or control software can be entirely or partiallyimplemented in the controller or else can be at least partiallyintegrated into other constituent parts of the cleaning device.

For example, the sensor can comprise at least one temperature sensor, inparticular at least one sensor element in the form of, for example, atemperature-dependent resistor, for example an NTC and/or a PTC.

The cleaning device can be configured to determine a current value of ametering operation of a disinfectant in the at least one cleaning fluidand/or at least one concentration of the at least one detergentconcentrate in the at least one cleaning fluid and/or at least one pHvalue. For example, the cleaning device can be configured to determine adetergent concentration in a washing liquid. For example, the cleaningdevice can be configured to determine a composition of the detergent, inparticular a pH value of the washing liquid in the recirculation tank.The cleaning device can have at least one sensor selected from the groupconsisting of a conductivity electrode, a pH probe, a redox probe, achlorine sensor. Recording can take place, for example, in a wash tankof the cleaning device. In particular, recording can take place in awash tank of the cleaning device in which corruption of the measurementvalues by incorporation of particles of dirt, for example table salt, islow, for example in a last wash tank. Recording a concentration of adetergent concentrate can take place using a quantity of detergent,which is supplied to a cleaning zone, and a quantity of regenerationwater. The cleaning device can have at least one throughflow sensor,and/or the quantity of detergent can be determined by means of scales.The quantity of regeneration water can be determined, for example, froma run time of a liquid transfer device.

The cleaning device can have at least one sensor for recording at leastone variable which characterizes a mechanical action of the at least onecleaning fluid on the items to be cleaned, in particular a pressureand/or a flow rate of the at least one cleaning fluid. For example, thesensor can comprise at least one sensor element in the form of apressure sensor, for example in the form of a micromechanical pressuresensor. The pressure sensor can be configured to record a systempressure in a washing system of the cleaning device. For example, thesensor can have a baffle plate sensor which can record an effect ofindividual nozzles, so-called reference nozzles. However, otherrefinements are also conceivable.

A hygiene value share is intended to be understood to mean, in general,a hygiene value per time period. The hygiene value share can be a valuewhich is to be achieved (desired value). The hygiene value share can bea value which is actually achieved (actual value). A time period can beunderstood to mean, in particular, a time duration and/or a unit oftime. An actual hygiene value which is achieved in a period of time canbe determined by adding up the hygiene value shares in the period oftime. For example, the hygiene value shares can be added up over thelength of a treatment zone or the time duration for which the items tobe cleaned are in this zone and therefore a hygiene value share for thetreatment zone can be determined. The hygiene value share for thetreatment zone can be referred to as the hygiene value share which thiszone contributes to the total result. As an alternative or in addition,a hygiene value share for a fixed time period can be taken into account,for example a hygiene value share per second. The hygiene value sharecan comprise a hygienization rate. A hygienization rate is intended tobe understood to mean a change over time. The relationship between theinfluencing variables and the respective hygiene value shares of saidinfluencing variables can be prespecified by at least one of thefollowing prespecifications: at least one calibration curve, inparticular at least one curve relating to a hygiene effect, wherein thecalibration curve respectively indicates a relationship between therespective hygiene value share of the influencing variable and a furtherinfluencing variable, wherein the at least one further influencingvariable is kept constant; at least one family of curves comprising aplurality of calibration curves, wherein the calibration curves eachindicate a relationship between the respective hygiene value share ofthe influencing variable and a further influencing variable, wherein theat least one further influencing variable is kept constant within eachcalibration curve of the family of curves, wherein the at least onefurther influencing variable distinguishes between the calibrationcurves of the family of curves; at least one calibration table, whereinthe calibration table respectively indicates a relationship between therespective hygiene value share of the influencing variable and a furtherinfluencing variable, wherein the at least one further influencingvariable is kept constant; at least one family of calibration tablescomprising a large number of calibration tables, wherein the calibrationtables each indicate a relationship between the respective hygiene valueshare of the influencing variable and a further influencing variable,wherein the at least one further influencing variable is kept constantwithin each calibration table of the family of tables, wherein the atleast one further influencing variable distinguishes between thecalibration tables of the family of tables. In this way, a dependency ofthe individual influencing variables in relation to one another can bedetermined. When taking into account at least two influencing variables,in particular all influencing variables, a multidimensional field can bedetermined, in which multidimensional field, as described in detailfurther below, the cleaning device, in particular the controller of thecleaning device, can vary the individual influencing variables.

The method can comprise at least one calibration. The relationshipbetween each influencing variable and the respective hygiene value shareof said influencing variable can be determined during the calibration.For example, the calibration can take place once, for example when firststarting up the cleaning device. For example, the calibration can takeplace repeatedly, for example at prespecifiable or selectable timeintervals. The relationship can be stored in at least one data memory,for example of the controller, after the calibration. For example, therelationship can be stored in a table, wherein, for example, thecalibration curves are stored as discrete values. During thecalibration, it is possible to determine how long is required, underrespective constant conditions, including prespecified constant valuesof the influencing variables, until the prespecified desired hygienevalue is achieved, in particular a prespecified reduction factor or aprespecified reduction in at least one target germ, wherein the hygienevalue share is determined from this information about the time duration,taking into account an initial hygiene value, the desired hygiene valueand the time duration.

An expected actual hygiene value is understood to mean, in general, anexpected hygiene result which is achieved at the end of the cleaning.Ascertaining the expected actual hygiene value can comprise taking intoaccount and/or adding up all previously achieved hygiene value shares,that is to say hygiene value shares achieved up to the time at which theexpected actual hygiene value is ascertained. In particular, all hygienevalue shares acting on the items to be cleaned since a start time of acleaning program can be taken into account and/or added up. The expectedactual hygiene value can be a prediction of the actual hygiene value atthe end of the cleaning. The expected actual hygiene value at the end ofthe cleaning can be determined from the hygiene value shares assumingthat the current influencing variables remain unchanged for the rest ofthe cleaning. The expected actual hygiene value at the end of thecleaning can be calculated from the hygiene value shares using at leastone algorithm selected from the group consisting of: integration of thesum of the hygiene value shares of the influencing variables over theexpected remaining duration of the cleaning; a totality of the Riemannsums with respect to time of the respective hygiene value shares of theinfluencing variables over the expected remaining duration of thecleaning. An end of cleaning can be understood to mean an end in respectof time in a single-chamber machine and/or automatic programmed washerand/or an end of a tunnel in the case of a conveyor washer.

The method comprises comparing the expected actual hygiene value withthe desired hygiene value. Comparison of the expected actual hygienevalue with the desired hygiene value is understood to mean, in general,determining an equality or a deviation in, in particular an overshootingand/or undershooting of, the expected actual hygiene value and thedesired hygiene value. The comparison can comprise a mathematicalcomparison. In particular, method step e. can comprise identifyingwhether the expected actual hygiene value is lower than the desiredhygiene value.

The method comprises influencing at least one influencing variabledepending on the result of the comparison. In particular, the cleaningdevice can be configured to influence at least one influencing variablein such a way that an actual hygiene value which is actually achieved atthe end of the cleaning corresponds to the desired hygiene value.

Influencing is generally understood to mean a change and/or variationand/or adjustment and/or regulation of at least one influencingvariable. Influencing of the at least one influencing variable can takeplace at prespecified or prespecifiable times. For example, aninfluencing time can be stored in a data memory of the controller of thecleaning device. The controller can be configured to prespecify aninfluencing time. For example, an influencing time can be selected, inparticular by the controller and/or a user. Influencing can take placeat a time during a cleaning program. For example, comparing the expectedactual hygiene value and the desired hygiene value can take place at theend of a cleaning step of the cleaning program and influencing of the atleast one influencing variable can take place in a subsequent cleaningstep. For example, in a conveyor washer, influencing can take place at aprespecified time during the transportation of the items to be cleaned,for example at a specific location, in particular between two cleaningzones. As mentioned above, a relationship between the respective hygienevalue share of the influencing variable and a further influencingvariable, for example in the form of a family of curves, can bedetermined, for example in a calibration step. The cleaning device, inparticular the controller, can be configured to determine a dependencyof the individual influencing variables, in particular at least twoinfluencing variables, in relation to one another. The cleaning device,in particular the controller, is preferably configured to determine adependency of each individual influencing variable in relation to eachother influencing variable. The cleaning device can be configured todetermine a multidimensional field in which the individual influencingvariables can be varied. Influencing can take place only withinprespecified and/or prespecifiable limits for each influencing variable.

For example, the duration of the cleaning can be changed when it isidentified during the comparison that the expected actual hygiene valuediffers from the desired hygiene value. In particular, the duration ofthe cleaning can be increased when it is identified that the expectedactual hygiene value is lower than the desired hygiene value. Inparticular, the duration of the cleaning can be reduced when it isidentified that the expected actual hygiene value is higher than thedesired hygiene value. It is possible for at least one measure forchanging the duration of the cleaning to be used, said measure beingselected from the group consisting of: at least one program duration ofat least one cleaning program is changed; at least one transportationspeed of at least one transportation device, by means of which the itemsto be cleaned are transported through the at least one cleaning chamber,is changed. For example, a program run time can be increased orshortened. For example, an action duration can be increased orshortened. A change in a transportation speed of a transportationdevice, for example a conveyor belt, can take place for example in thecase of a conveyor washer. For example, the transportation speed can beincreased or slowed down. The transportation speed can be reduced downto intermittent operation, in the case of which the transportationdevice is stopped. In the case of intermittent operation, regions of thetransportation device, in particular of the conveyor belt, can remain ina cleaning zone, for example the fresh water rinse arrangement, so thatthe action time is extended. For example, in the case of cleaningdevices with thermal disinfection, the transportation device can bestopped when a specific temperature is undershot. For example, in thecase of cleaning devices with chemical disinfection, the transportationdevice can be stopped when the disinfection component is missing. Thetransportation speed can additionally be reduced when the time-resolvedrecording of the at least one influencing variable has not taken placeand/or a sensor signal has not been generated by the at least one sensorfor recording the influencing variable and/or transmitted to thecontroller and/or the controller, in particular the data memory, doesnot contain any information and/or a value of the influencing variable.

For example, at least one concentration of at least one additive in theat least one cleaning fluid can be changed when it is identified thatthe expected actual hygiene value differs from the desired hygienevalue. The at least one concentration of the at least one additive inthe at least one cleaning fluid can be increased when it is identifiedthat the expected actual hygiene value undershoots the desired hygienevalue. Therefore, it is possible, for example, to compensate for arelatively low hygiene effect from the thermal influence, for example inthe case of a drop in a temperature of the cleaning fluid, for example awashing liquid in a recirculation tank, by increasing the concentrationof the at least one additive in the at least one cleaning fluid and/or,as described further below, changing the composition of at least oneadditive in the at least one cleaning fluid, without extending a runtime, in particular a washing time. The additive can comprise at leastone substance selected from the group consisting of a detergentconcentrate and a disinfectant, in particular chlorine. Otherdisinfectants can be or contain, for example, bromine, iodine orhydrogen peroxide. Within the scope of the present application, theexpression ‘detergent’ is used synonymously with the expression‘additive.’

For example, an increase in a share and/or additional metering ofdisinfection components can take place. For example, the controller canbe configured to activate at least one metering device of the cleaningdevice more frequently and/or for a longer time duration. For example,the controller can be configured to increase a delivery volume of themetering device in the event of continuous running of the meteringdevice. In one embodiment, the cleaning device can have a first and asecond metering device. The first metering device can be operatedcontinuously, for example at a basic setting. The controller can beconfigured to activate the second metering device and therefore supplyadditional additives in the case of the concentration and/or themetering being influenced. This is particularly advantageous since thefirst and the second metering device can be of simple design. Theadditives supplied by the first and the second metering device candiffer. For example, an additive of the second metering device cancontain a disinfection component. Therefore, cleaning at lowtemperatures can be rendered possible in particular. For example, a usercan select a low temperature and/or the cleaning device can beconfigured to identify that washing can be performed at low temperaturesand to reduce temperatures in the cleaning process.

The method can comprise a detection step in which, in particular beforea change in a concentration and/or metering, determining a currentconcentration and/or metering takes place. For example, at least one,above-described, sensor can be used in the detection step, which sensoris configured to determine the current value for metering of adisinfectant in the at least one cleaning fluid and/or at least oneconcentration of the at least one detergent concentrate in the at leastone cleaning fluid and/or at least one pH value. The change in theconcentration and/or metering can take place within a prespecifiableand/or prespecified limit. For example, an upper limit for metering canbe 4 g of detergent per liter of tank contents.

For example, at least one mechanical application of the at least onecleaning fluid to the items to be cleaned can be changed when it isidentified during the comparison that the expected actual hygiene valuediffers from the desired hygiene value. In particular, an intensity ofthe mechanical application can be increased when it is identified thatthe expected actual hygiene value is lower than the desired hygienevalue. In particular, an intensity of the mechanical application can belowered when it is identified that the expected actual hygiene value ishigher than the desired hygiene value. For example, at least one measurefor changing the intensity of the mechanical application can be used,which measure is selected from the group consisting of: at least onepressure of the at least one cleaning fluid is changed; at least oneflow rate of the at least one cleaning fluid is changed. For example,increasing the mechanical effect can take place by switching on furtherapplication devices, for example further nozzles. For example, a pumpingcapacity of the cleaning device can be increased, for example by using aseries circuit of pumps or at least one frequency converter.

The method can comprise a detection step in which, in particular beforea change in a mechanical effect, determining of a current mechanicaleffect takes place. As stated above, the cleaning device can havesensors which are configured to monitor the mechanical effect of thewashing system, in particular the application device. The sensors formonitoring the mechanical effect can be configured to identifymalfunctions in the washing system. The sensors for monitoring themechanical effect can be configured to identify that a system pressureis insufficient and/or that individual nozzles produce too small a jetof water or no jet of water. The sensors for monitoring the mechanicaleffect can be configured to transmit detection results of this kind tothe controller. The controller can be configured to influence anotherinfluencing variable as the mechanical effect in order to equalizemalfunctions in the washing system, in particular the applicationdevice, in order to achieve a desired hygiene value. A change in themechanical effect can take place within a predefinable and/or predefinedlimit. For example, an upper limit for a mechanical effect can beprovided in that damage to the items to be cleaned is intended to beavoided.

For example, a volume flow in the final rinse arrangement can beincreased, for example a fresh water final rinse arrangement and/or pumpfinal rinse arrangement. The method can comprise a detection step inwhich, in particular before a change in the volume flow of the finalrinse arrangement, determining of a current volume flow takes place. Forexample, the cleaning device can have at least one sensor which isconfigured to determine a throughflow in the fresh water final rinsearrangement. For example, the cleaning device can have at least onesensor which is configured to record a pressure and/or throughflow inthe pump final rinse arrangement.

For example, an increase in the temperature, in particular in individualtanks and/or cleaning zones, can take place. The method can comprise adetection step in which, in particular before a change in thetemperature, determining of a current temperature takes place, forexample using one or more temperature sensors.

In method step f., an influencing measure can be used for influencingthe at least one influencing variable, wherein the influencing measuretakes place depending on a prespecified and/or prespecifiable hierarchyof measures. The hierarchy of measures can be stored in the controller,for example in the form of a program code. The hierarchy of measures canbe selected taking into account a decision basis selected from the groupconsisting of: speed at which a process can be influenced, for exampleinertia of sensors and of the process; real expenditure for influencingthe at least one influencing variable, for example expenditure onequipment, costs and susceptibility to faults; costs to the user and/oroperator, for example costs of cleaning chemicals. For example, thetemperature of the at least one cleaning fluid can be increased when thedesired hygiene value is undershot. The cleaning device can beconfigured to identify whether the required temperature is reachedwithin a prespecified time window after the increase in temperature istriggered and to initiate regulation of the metering if said temperatureis not reached. Influencing the metering can have a great influence onoperating costs. In addition, tracking the concentration may requirelonger than influencing other influencing variables, so that changingthe metering can be arranged after influencing of other influencingvariables in the hierarchy of measurements, in particular at the end ofthe hierarchy of measurements. In particular a so-called overkill due toexcessive detergent, in particular additives, can be avoided in this wayand optimum use of the cleaning chemicals in an advantageous manner inrespect of the environment and expense to the operator can be achieved.For example, influencing can take place in the following order:

-   -   influencing of the duration of the cleaning;    -   influencing of the mechanical effect;    -   influencing of the effect of a final rinse arrangement;    -   influencing of the concentration and/or metering and/or at least        one pH value;    -   influencing of the temperature of the at least one cleaning        fluid.

In the method, the items to be cleaned can be transported through the atleast one cleaning chamber by means of the at least one transportationdevice.

The items to be cleaned can comprise a plurality of items to be cleaned,wherein each item is allocated a hygienization account in which previoushygienization units to which the item has been subjected arecumulatively stored. A hygienization unit is understood to mean avariable which quantifies the influence on germ reduction. A number ofhygienization units can be assigned to each hygienization processdepending on the influence on germ reduction. For example, a desiredhygiene result for one item to be cleaned can be 1000 hygienizationunits, so that 1000 hygienization units are required to achieve thedesired hygiene value. Zero hygienization units can mean that the itemhas not previously been subjected to any hygienization process. Ahygienization account can be understood to mean, in principle, a storednumber of accumulated hygienization units. The hygienization account canbe stored, for example, in a data memory of the controller. The items tobe cleaned can comprise a plurality of items to be cleaned, wherein thetransportation device is subdivided into sections, wherein each sectionis allocated a hygienization account in which previous hygienizationunits to which the item held in the respective section has beensubjected are cumulatively stored. The hygienization account can bereset to zero when a fault in the cleaning process is established. Forexample, the hygienization account can be set to zero when the cleaningchamber is opened.

The cleaning chamber can be subdivided into a plurality of cleaningzones, wherein each cleaning zone has at least one application device,wherein the items to be cleaned are transported through the cleaningzones by means of the transportation device one after the other. Themethod can comprise at least one checking step, wherein the checkingstep is carried out until the items to be cleaned are located within thelast cleaning zone in a transportation direction of the transportationdevice. During the checking step, the expected actual hygiene value canbe once again compared with the desired hygiene value and at least onesafety measure can be taken when the desired hygiene value is undershot.The safety measure can comprise at least one measure selected from thegroup consisting of: the transportation device is stopped; thetransportation device is slowed down; a pressure of the cleaning fluidin the application device of the last cleaning zone is increased; a flowrate of the cleaning fluid in the application device of the lastcleaning zone is increased. The last cleaning zone can be a final rinsezone, in particular a fresh water final rinse zone.

A further aspect proposes a cleaning device for cleaning items to becleaned. The cleaning device comprises at least one cleaning chamber andat least one application device for applying at least one cleaning fluidto the items to be cleaned in the cleaning chamber. The cleaning devicefurther comprises:

-   -   I. at least one data memory for storing a prespecification for a        desired hygiene value which is to be achieved with the cleaning;    -   II. at least two measuring devices for time-resolved recording        of at least two influencing variables which have an influence on        a hygienization of the items to be cleaned;    -   III. at least one determining device for determining hygiene        value shares from the influencing variables using a prespecified        relationship between each influencing variable and the        respective hygiene value share of said influencing variable;    -   IV. at least one evaluating device for ascertaining an expected        actual hygiene value at the end of the cleaning from the hygiene        value shares;    -   V. at least one comparing device for comparing the expected        actual hygiene value with the desired hygiene value; and    -   VI. at least one influencing device for influencing at least one        influencing variable depending on the result of the comparison.

The cleaning device can be configured, in particular, to carry out amethod according to one or more of the refinements presented above.Accordingly, reference can be made to the above description for possiblerefinements of the cleaning device.

The cleaning device can have a controller. The data memory, thedetermining device, the evaluating device, the comparing device and theinfluencing device can be constituent parts of the controller. Thecontroller can comprise at least one data processing device, inparticular at least one processor or data processor. The data processingdevice can be programmed to allocate in each case one hygiene valueshare to the influencing variables on the basis of the prespecifiedrelationship and to determine the expected actual hygiene value at theend of the cleaning from the hygiene value shares. The data processingdevice can further be programmed to compare the expected actual hygienevalue with the desired hygiene value. The data processing device canfurther be programmed to identify whether the expected actual hygienevalue is lower than the desired hygiene value. The data processingdevice can further be programmed to influence the at least oneinfluencing variable depending on the result of the comparison.

The data memory can comprise at least one memory selected from avolatile data memory and a nonvolatile data memory.

A measuring device (also referred to as a “recorder”) is understood tomean, in general, a device which is configured to record at least oneinfluencing variable in a time-resolved manner. The measuring devicescan comprise at least two sensors selected from the group consisting of:at least one temperature sensor for recording at least one temperatureof the at least one cleaning fluid; at least one mechanical or fluidicsensor for recording at least one measurement variable of a mechanicalaction of the at least one cleaning fluid on the items to be cleaned, inparticular at least one pressure sensor for recording at least onepressure of the at least one cleaning fluid and/or at least one flowsensor for recording at least one flow of the at least one cleaningfluid; at least one concentration sensor for recording at least oneconcentration of at least one disinfectant in the at least one cleaningfluid; at least one concentration sensor for recording at least oneconcentration of at least one detergent concentrate in the at least onecleaning fluid; at least one pH sensor for recording at least one pHvalue of the at least one cleaning fluid. In particular, the measuringdevice can be configured to carry out method step b.

A determining device is understood to mean, in general, a device whichis configured to determine hygiene value shares from the influencingvariables using a prespecified relationship between each influencingvariable and the respective hygiene value share of said influencingvariable. In particular, the determining device can be configured tocarry out method step c. An evaluating device is understood to mean, inprinciple, a device which is configured to ascertain an expected actualhygiene value at an end of the cleaning from the hygiene value shares. Acomparing device is understood to mean, in principle, a device which isconfigured to compare the expected actual hygiene value with the desiredhygiene value. An influencing device is understood to mean, in general,a device which is configured to influence at least one influencingvariable depending on the result of the comparison. As stated above, thecleaning device can have a controller, wherein the determining device,the evaluating device, the comparing device and the influencing deviceare constituent parts of the controller. For example, the determiningdevice, the evaluating device, the comparing device and the influencingdevice comprise processors, in particular microprocessors.

The cleaning device can be selected from the group consisting of aconveyor washer and an automatic programmed washer.

The proposed method and the proposed cleaning device have numerousadvantages over known methods and cleaning devices. Therefore, precisecontrol and monitoring of the hygiene effect is possible and improvementin the operational reliability taking into account the hygiene aspectsis possible. In particular, a so-called overkill due to excessivedetergent, in particular additives, can be avoided and therefore optimumuse of the cleaning chemicals in an advantageous manner in respect ofthe environment and expense to the operator can be achieved. In the caseof a drop in a temperature of the cleaning fluid in the recirculationtank, increasing the concentration of the detergent and/or changing thecomposition of the detergent in the recirculation tank can compensatefor a relatively low hygiene effect from the thermal influence, withoutextending a washing time.

In summary, the following embodiments are particularly preferred withinthe scope of this disclosure:

Embodiment 1: a method for cleaning items to be cleaned, wherein acleaning device having at least one cleaning chamber and at least oneapplication device for applying at least one cleaning fluid to the itemsto be cleaned in the cleaning chamber is used, wherein the methodcomprises the following steps:

-   -   a. prespecifying a desired hygiene value which is to be achieved        with the cleaning;    -   b. time-resolved recording of at least two influencing variables        which have an influence on a hygienization of the items to be        cleaned;    -   c. determining hygiene value shares from the influencing        variables using a prespecified relationship between each        influencing variable and the respective hygiene value share of        said influencing variable;    -   d. ascertaining an expected actual hygiene value at the end of        the cleaning from the hygiene value shares;    -   e. comparing the expected actual hygiene value with the desired        hygiene value; and    -   f. influencing at least one influencing variable depending on        the result of the comparison.

Embodiment 2: the method according to the preceding embodiment, whereinmethod step e. further comprises identifying whether the expected actualhygiene value is lower than the desired hygiene value.

Embodiment 3: the method according to either of the precedingembodiments, wherein the hygiene value share comprises a hygienizationrate.

Embodiment 4: the method according to one of the preceding embodiments,wherein the desired hygiene value is selected from the group consistingof: an A0 value according to DIN EN ISO 15883 which is to be achievedoverall with the cleaning; a hygiene level which is to be achievedaccording to DIN 10510, at the desired prespecifications for tank andboiler temperatures according to DIN 10510; a number of HUE unitsaccording to the NSF3 standard which are to be achieved overall with thecleaning; a reduction in a population of a target germ which is to beachieved overall with the cleaning, in particular a reduction in thepopulation of Staphylococcus aureus which is to be achieved overall withthe cleaning.

Embodiment 5: the method according to the preceding embodiment, whereinthe desired hygiene value corresponds to 99.999% death of a populationof Staphylococcus aureus.

Embodiment 6: the method according to one of the preceding embodiments,wherein the influencing variables are selected from the group consistingof: a duration of the cleaning; at least one temperature of the at leastone cleaning fluid; at least one measurement variable which ischaracteristic of a mechanical action of the at least one cleaning fluidon the items to be cleaned, in particular a pressure and/or a flow rateof the at least one cleaning fluid; at least one concentration of atleast one disinfectant in the at least one cleaning fluid; at least oneconcentration of at least one detergent concentrate in the at least onecleaning fluid; at least one pH value of the at least one cleaningfluid; at least one measurement variable which is characteristic of aneffect of a final rinse operation.

Embodiment 7: the method according to one of the preceding embodiments,wherein the at least two influencing variables comprise, as firstinfluencing variable, at least one temperature of the at least onecleaning fluid and furthermore at least one further influencingvariable.

Embodiment 8: the method according to one of the preceding embodiments,wherein the time-resolved recording of the at least two influencingvariables takes place at prespecified or prespecifiable times or atprespecified or prespecifiable intervals.

Embodiment 9: the method according to one of the preceding embodiments,wherein influencing of the at least one influencing variable takes placeat prespecified or prespecifiable times.

Embodiment 10: the method according to one of the preceding embodiments,wherein the relationship between the influencing variables and therespective hygiene value shares of said influencing variables isprespecified by at least one of the following prespecifications: atleast one calibration curve, in particular at least one curve relatingto a hygiene effect, wherein the calibration curve respectivelyindicates a relationship between the respective hygiene value share ofthe influencing variable and a further influencing variable, wherein theat least one further influencing variable is kept constant; at least onefamily of curves comprising a plurality of calibration curves, whereinthe calibration curves each indicate a relationship between therespective hygiene value share of the influencing variable and a furtherinfluencing variable, wherein the at least one further influencingvariable is kept constant within each calibration curve of the family ofcurves, wherein the at least one further influencing variabledistinguishes between the calibration curves of the family of curves; atleast one calibration table, wherein the calibration table respectivelyindicates a relationship between the respective hygiene value share ofthe influencing variable and a further influencing variable, wherein theat least one further influencing variable is kept constant; at least onefamily of calibration tables comprising a plurality of calibrationtables, wherein the calibration tables each indicate a relationshipbetween the respective hygiene value share of the influencing variableand a further influencing variable, wherein the at least one furtherinfluencing variable is kept constant within each calibration table ofthe family of tables, wherein the at least one further influencingvariable distinguishes between the calibration tables of the family oftables.

Embodiment 11: the method according to one of the preceding embodiments,wherein the method comprises at least one calibration, wherein therelationship between each influencing variable and the respectivehygiene value share of said influencing variable is determined duringthe calibration.

Embodiment 12: the method according to the preceding embodiment, whereinthe relationship is stored in at least one data memory after thecalibration.

Embodiment 13: the method according to either of the two precedingembodiments, wherein, during the calibration, it is determined how longis required, under respective constant conditions, includingprespecified constant values of the influencing variables, until theprespecified desired hygiene value is achieved, in particular aprespecified reduction factor or a prespecified reduction in at leastone target germ, wherein the hygiene value share is determined from thisinformation about the time duration, taking into account an initialhygiene value, the desired hygiene value and the time duration.

Embodiment 14: the method according to one of the preceding embodiments,wherein the expected actual hygiene value at the end of the cleaning isdetermined from the hygiene value shares assuming that the currentinfluencing variables remain unchanged for the rest of the cleaning.

Embodiment 15: the method according to one of the preceding embodiments,wherein the expected actual hygiene value at the end of the cleaning iscalculated from the hygiene value shares using at least one algorithmselected from the group consisting of: integration of the sum of thehygiene value shares of the influencing variables over the expectedremaining duration of the cleaning; a totality of the Riemann sums withrespect to time of the respective hygiene value shares of theinfluencing variables over the expected remaining duration of thecleaning.

Embodiment 16: the method according to one of the preceding embodiments,wherein the duration of the cleaning is changed when it is identifiedduring the comparison that the expected actual hygiene value differsfrom the desired hygiene value.

Embodiment 17: the method according to the preceding embodiment, whereinthe duration of the cleaning is increased when it is identified that theexpected actual hygiene value is lower than the desired hygiene value.

Embodiment 18: the method according to either of the two precedingembodiments, wherein the duration of the cleaning is reduced when it isidentified that the expected actual hygiene value is higher than thedesired hygiene value.

Embodiment 19: the method according to one of the three precedingembodiments, wherein at least one measure for changing the duration ofthe cleaning is used, said measure being selected from the groupconsisting of: at least one program duration of at least one cleaningprogram is changed; at least one transportation speed of at least onetransportation device, by means of which the items to be cleaned aretransported through the at least one cleaning chamber, is changed.

Embodiment 20: the method according to one of the preceding embodiments,wherein at least one concentration of at least one additive in the atleast one cleaning fluid is changed when it is identified that theexpected actual hygiene value differs from the desired hygiene value.

Embodiment 21: the method according to the preceding embodiment, whereinthe at least one concentration of the at least one additive in the atleast one cleaning fluid is increased when it is identified that theexpected actual hygiene value undershoots the desired hygiene value.

Embodiment 22: the method according to either of the two precedingembodiments, wherein the additive comprises at least one substanceselected from the group consisting of a detergent concentrate and adisinfectant, in particular chlorine.

Embodiment 23: the method according to one of the preceding embodiments,wherein at least one mechanical application of the at least one cleaningfluid to the items to be cleaned is changed when it is identified duringthe comparison that the expected actual hygiene value differs from thedesired hygiene value.

Embodiment 24: the method according to the preceding embodiment, whereinan intensity of the mechanical application is increased when it isidentified that the expected actual hygiene value is lower than thedesired hygiene value.

Embodiment 25: the method according to either of the two precedingembodiments, wherein an intensity of the mechanical application isreduced when it is identified that the expected actual hygiene value ishigher than the desired hygiene value.

Embodiment 26: the method according to one of the three precedingembodiments, wherein at least one measure for changing the intensity ofthe mechanical application is used, said measure being selected from thegroup consisting of: at least one pressure of the at least one cleaningfluid is changed; at least one flow rate of the at least one cleaningfluid is changed.

Embodiment 27: the method according to one of the preceding embodimentswherein, in f., an influencing measure is used for influencing the atleast one influencing variable, wherein the influencing measure takesplace depending on a prespecified and/or prespecifiable hierarchy ofmeasures.

Embodiment 28: the method according to one of the preceding embodiments,wherein the items to be cleaned are transported through the at least onecleaning chamber by means of at least one transportation device.

Embodiment 29: the method according to the preceding embodiment, whereinthe items to be cleaned comprise a plurality of items to be cleaned,wherein each item is allocated a hygienization account in which previoushygienization units to which the items have been subjected arecumulatively stored.

Embodiment 30: the method according to either of the two precedingembodiments, wherein the items to be cleaned comprise a plurality ofitems to be cleaned, wherein the transportation device is subdividedinto sections, wherein each section is allocated a hygienization accountin which previous hygienization units to which the items held in therespective section have been subjected are cumulatively stored.

Embodiment 31: the method according to either of the two precedingembodiments, wherein the hygienization account is reset to zero when afault in the cleaning process is established.

Embodiment 32: the method according to one of the four precedingembodiments, wherein the cleaning chamber is subdivided into a pluralityof cleaning zones, wherein each cleaning zone has at least oneapplication device, wherein the items to be cleaned are transportedthrough the cleaning zones by means of the transportation device oneafter the other.

Embodiment 33: the method according to the preceding embodiment, whereinthe method comprises at least one checking step, wherein the checkingstep is carried out until the items to be cleaned are located within thelast cleaning zone in a transportation direction of the transportationdevice, wherein, during the checking step, the expected actual hygienevalue is once again compared with the desired hygiene value and whereinat least one safety measure is taken when the desired hygiene value isundershot.

Embodiment 34: the method according to the preceding embodiment, whereinthe safety measure comprises at least one measure selected from thegroup consisting of: the transportation device is stopped; thetransportation device is slowed down; a pressure of the cleaning fluidin the application device of the last cleaning zone is increased; a flowrate of the cleaning fluid in the application device of the lastcleaning zone is increased.

Embodiment 35: the method according to either of the two precedingembodiments, wherein the last cleaning zone is a final rinse zone, inparticular a fresh water final rinse zone.

Embodiment 36: a cleaning device for cleaning items to be cleaned,comprising at least one cleaning chamber and at least one applicationdevice for applying at least one cleaning fluid to the items to becleaned in the cleaning chamber, wherein the cleaning device furthercomprises:

-   I. at least one data memory for storing a prespecification for a    desired hygiene value which is to be achieved with the cleaning;-   II. at least two measuring devices for time-resolved recording of at    least two influencing variables which have an influence on a    hygienization of the items to be cleaned;-   III. at least one determining device for determining hygiene value    shares from the influencing variables using a prespecified    relationship between each influencing variable and the respective    hygiene value share of said influencing variable;-   IV. at least one evaluating device for ascertaining an expected    actual hygiene value at the end of the cleaning from the hygiene    value shares;-   V. at least one comparing device for comparing the expected actual    hygiene value with the desired hygiene value; and-   VI. at least one influencing device for influencing at least one    influencing variable depending on the result of the comparison.

Embodiment 37: the cleaning device according to the precedingembodiment, wherein the cleaning device is configured to carry out amethod according to one of the preceding embodiments.

Embodiment 38: the cleaning device according to one of the precedingembodiments which relates to a cleaning device, wherein the cleaningdevice has at least one controller, wherein the data memory, thedetermining device, the evaluating device, the comparing device and theinfluencing device are constituent parts of the controller.

Embodiment 39: the cleaning device according to the precedingembodiment, wherein the controller comprises at least one dataprocessing device, in particular at least one processor.

Embodiment 40: the cleaning device according to the precedingembodiment, wherein the data processing device is programmed to allocatein each case one hygiene value share to the influencing variables on thebasis of the prespecified relationship and to determine the expectedactual hygiene value at the end of the cleaning from the hygiene valueshares.

Embodiment 41: the cleaning device according to the precedingembodiment, wherein the data processing device is further programmed tocompare the expected actual hygiene value with the desired hygiene valueand to identify whether the expected actual hygiene value is lower thanthe desired hygiene value.

Embodiment 42: the cleaning device according to the precedingembodiment, wherein the data processing device is further programmed toinfluence the at least one influencing variable depending on the resultof the comparison.

Embodiment 43: the cleaning device according to one of the precedingembodiments which relates to a cleaning device, wherein the data memorycomprises at least one memory selected from a volatile data memory and anonvolatile data memory.

Embodiment 44: the cleaning device according to one of the precedingembodiments which relates to a cleaning device, wherein the measuringdevices comprise at least two sensors selected from the group consistingof: at least one temperature sensor for recording at least onetemperature of the at least one cleaning fluid; at least one mechanicalor fluidic sensor for recording at least one measurement variable of amechanical action of the at least one cleaning fluid on the items to becleaned, in particular at least one pressure sensor for recording atleast one pressure of the at least one cleaning fluid and/or at leastone flow sensor for recording at least one flow of the at least onecleaning fluid; at least one concentration sensor for recording at leastone concentration of at least one disinfectant in the at least onecleaning fluid; at least one concentration sensor for recording at leastone concentration of at least one detergent concentrate in the at leastone cleaning fluid; at least one pH sensor for recording at least one pHvalue of the at least one cleaning fluid.

Embodiment 45: the cleaning device according to one of the precedingembodiments which relates to a cleaning device, wherein the cleaningdevice is selected from the group consisting of a conveyor washer and anautomatic programmed washer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned aspects of exemplary embodiments will become moreapparent and will be better understood by reference to the followingdescription of the embodiments taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 shows an exemplary embodiment of a method according to thisdisclosure;

FIG. 2 shows an exemplary embodiment of a cleaning device according tothis disclosure;

FIG. 3 shows a comparison of the achieved hygiene value shares persecond according to A0 methods, according to HUE methods and accordingto SUE methods; and

FIG. 4 shows a prespecified relationship between the influencingvariable temperature, the hygiene value share of said influencingvariable according to the SUE method and the concentration.

DESCRIPTION

The embodiments described below are not intended to be exhaustive or tolimit the invention to the precise forms disclosed in the followingdetailed description. Rather, the embodiments are chosen and describedso that others skilled in the art may appreciate and understand theprinciples and practices of this disclosure.

FIG. 1 schematically illustrates an exemplary embodiment of a methodaccording to this disclosure for cleaning items 143 to be cleaned. Themethod comprises specifying a desired hygiene value 110 which is to beachieved with the cleaning. The desired hygiene value can be selectedfrom the group consisting of: an A0 value according to DIN EN ISO 15883which is to be achieved overall with the cleaning; a hygiene levelaccording to DIN 10510 which is to be achieved, at the desiredprespecifications for tank and boiler temperatures according to DIN10510; a number of HUE units according to the NSF3 standard which are tobe achieved overall with the cleaning; a reduction in a population of atarget germ which is to be achieved overall with the cleaning, inparticular a reduction in the population of Staphylococcus aureus whichis to be achieved overall with the cleaning. The desired hygiene valuecan correspond to 99.999% death of a population of Staphylococcusaureus. The hygiene value can preferably be a SUE value. The SUE valueper second can be a measure of the reduction in the target germ, whichmeasure takes into account the dependency on the temperature and thedetergent chemicals used, where

SUE/sec=Ae ^(BT),

where A=1/7000000 and B=0.191. Here, a SUE value of 100 corresponds to a5 log-level reduction in the target germ. The parameters A and B areempirical values determined using a population of Staphylococcus aureusas target germ population. For example, the prespecification of thedesired hygiene value 110 which is to be achieved with the cleaning cancomprise selecting a desired hygiene value from a list and/or entering adesired hygiene value, for example into a man/machine interface of thecleaning device 126, in particular of a controller 118 of the cleaningdevice 126.

The method comprises time-resolved recording of at least two influencingvariables 112 which have an influence on a hygienization of the items143 to be cleaned. The influencing variables can be selected from thegroup consisting of: a duration of the cleaning; at least onetemperature of the at least one cleaning fluid; at least one measurementvariable which is characteristic of a mechanical action of the at leastone cleaning fluid on the items 143 to be cleaned, in particular apressure and/or a flow rate of the at least one cleaning fluid; at leastone concentration of at least one disinfectant in the at least onecleaning fluid; at least one concentration of at least one detergentconcentrate in the at least one cleaning fluid; at least one pH value ofthe at least one cleaning fluid; at least one measurement variable whichis characteristic of an effect of a final rinse operation. Theinfluencing variables can influence each other. A reduction in one ofthese influencing variables can respectively be compensated for byincreasing one or more of the other influencing variables. The at leasttwo influencing variables can comprise, as first influencing variable,at least one temperature of the at least one cleaning fluid andfurthermore at least one further influencing variable.

The method comprises determining hygiene value shares from theinfluencing variables 114 using a prespecified relationship between eachinfluencing variable and the respective hygiene value share of saidinfluencing variable. The relationship between the influencing variablesand the respective hygiene value shares of said influencing variablescan be prespecified by at least one of the following prespecifications:at least one calibration curve, in particular at least one curverelating to a hygiene effect, wherein the calibration curve respectivelyindicates a relationship between the respective hygiene value share ofthe influencing variable and a further influencing variable, wherein theat least one further influencing variable is kept constant; at least onefamily of curves comprising a plurality of calibration curves, whereinthe calibration curves each indicate a relationship between therespective hygiene value share of the influencing variable and a furtherinfluencing variable, wherein the at least one further influencingvariable is kept constant within each calibration curve of the family ofcurves, wherein the at least one further influencing variabledistinguishes between the calibration curves of the family of curves; atleast one calibration table, wherein the calibration table respectivelyindicates a relationship between the respective hygiene value share ofthe influencing variable and a further influencing variable, wherein theat least one further influencing variable is kept constant; at least onefamily of calibration tables comprising a plurality of calibrationtables, wherein the calibration tables each indicate a relationshipbetween the respective hygiene value share of the influencing variableand a further influencing variable, wherein the at least one furtherinfluencing variable is kept constant within each calibration table ofthe family of tables, wherein the at least one further influencingvariable distinguishes between the calibration tables of the family oftables. In this way, a dependency of the individual influencingvariables in relation to one another can be determined. When taking intoaccount at least two influencing variables, in particular allinfluencing variables, a multidimensional field can be determined, inwhich multidimensional field the individual influencing variables can bevaried.

The method can comprise at least one calibration 116 in which therelationship between each influencing variable and the respectivehygiene value share of said influencing variable can be determined. Forexample, the calibration 116 can take place once, for example at firststart-up. For example, the calibration 116 can take place repeatedly,for example at prespecifiable or selectable time intervals. Therelationship can be stored in at least one data memory, for example of acontroller 118, after the calibration 116. For example, the relationshipcan be stored in a table, wherein, for example, the calibration curvesare stored as discrete values. During the calibration 116, it ispossible to determine how long is required, under respective constantconditions, including prespecified constant values of the influencingvariables, until the prespecified desired hygiene value is achieved, inparticular a prespecified reduction factor or a prespecified reductionin at least one target germ, wherein the hygiene value share isdetermined from this information about the time duration, taking intoaccount an initial hygiene value, the desired hygiene value and the timeduration.

The method comprises ascertaining an expected actual hygiene value atthe end of the cleaning from the hygiene value shares 120. Ascertainingthe expected actual hygiene value 120 can comprise taking into accountand/or adding up all previously achieved hygiene value shares, that isto say hygiene value shares achieved up to the time at which theexpected actual hygiene value 120 is ascertained. In particular, allhygiene value shares acting on the items 143 to be cleaned since a starttime of a cleaning program can be taken into account and/or added up.The expected actual hygiene value can be a prediction of the actualhygiene value at the end of the cleaning. The expected actual hygienevalue at the end of the cleaning can be determined from the hygienevalue shares assuming that the current influencing variables remainunchanged for the rest of the cleaning. The expected actual hygienevalue at the end of the cleaning can be calculated from the hygienevalue shares using at least one algorithm selected from the groupconsisting of: integration of the sum of the hygiene value shares of theinfluencing variables over the expected remaining duration of thecleaning; a totality of the Riemann sums with respect to time of therespective hygiene value shares of the influencing variables over theexpected remaining duration of the cleaning.

The method comprises comparing the expected actual hygiene value withthe desired hygiene value 122. The comparison 122 can comprisedetermining overshooting and/or undershooting of the expected actualhygiene value and the desired hygiene value. The comparison 122 cancomprise a mathematical comparison. In particular, the comparison 122can comprise identifying whether the expected actual hygiene value islower than the desired hygiene value. The method comprises influencingor changing at least one influencing variable 124 depending on theresult of the comparison. Influencing of the at least one influencingvariable 124 can take place at prespecified or prespecifiable times.

FIG. 2 shows a schematic illustration of an embodiment of a cleaningdevice 126 having at least one cleaning chamber 128 and at least oneapplication device 130 for applying at least one cleaning fluid to theitems 143 to be cleaned in the cleaning chamber 128. The cleaning device126 comprises at least one data memory 132 for storing aprespecification for a desired hygiene value which is to be achievedwith the cleaning, at least two measuring devices 134, not illustratedin FIG. 2, for time-resolved recording of at least two influencingvariables which have an influence on a hygienization of the items 143 tobe cleaned, at least one determining device 136 for determining hygienevalue shares from the influencing variables using a prespecifiedrelationship between each influencing variable and the respectivehygiene value share of said influencing variable, at least oneevaluating device 138 for ascertaining an expected actual hygiene valueat the end of the cleaning from the hygiene value shares, at least onecomparing device 140 for comparing the expected actual hygiene valuewith the desired hygiene value, and at least one influencing device 142for influencing at least one influencing variable depending on theresult of the comparison. The data memory 132, the determining device136, the evaluating device 138, the comparing device 140 and theinfluencing device 142 can be constituent parts of the controller 118.

In the exemplary embodiment illustrated in FIG. 2, the items 143 to becleaned, for example in the form of dishes, can be conveyed through thecleaning chamber 128, for example in the form of a tunnel, by means ofat least one transportation device 144 in the transportation direction145. In FIG. 2, the transportation direction 145 is identified by anarrow. To this end, the cleaning device 126 can be configured, forexample, as a flight-type conveyor or as a rack conveyor. For example,at least one inlet 146, at which the items 143 to be cleaned are passedto the transportation device 144, and at least one outlet 148, at whichthe cleaned items 143 can be removed, can be provided. Thetransportation device 144 can accordingly comprise, for example, aconveyor belt. Other refinements are also possible. The transportationdevice 144 can comprise, for example, at least one drive 149.

The cleaning chamber 128 can be subdivided into a plurality of cleaningzones 150. In the cleaning zones 150, cleaning fluid can be applied tothe items 143 to be cleaned by means of the application device 130, forexample a fluid devices. Each cleaning zone 150 can have at least oneapplication device 130. For example, at least one nozzle system, notillustrated in FIG. 2, can be provided for this purpose, which nozzlesystem can be fed with cleaning fluid from a tank for example by meansof a pump, not illustrated in FIG. 2, and a line system, notillustrated. The items 143 to be cleaned can be transported through thecleaning zones 150 one after the other by means of the transportationdevice 144. In FIG. 2, the transportation path L and the length of thecleaning zones 150 are shown in mm.

In the embodiment shown in FIG. 2, the cleaning device 126 can have, forexample, a plurality of wash tanks 152 in which at least one cleaningfluid is applied to the items 143 to be cleaned at a temperature. Forexample, a wash zone nozzle system, not illustrated, can be provided inthe wash tanks 152, the so-called wash zone, which wash zone nozzlesystem can be fed with cleaning fluid from a washing tank, for example,by means of a pump, likewise not illustrated, and a line system,likewise not illustrated. Furthermore, the cleaning device 126 can haveone or more thermal disinfection zones 154 which are configured to carryout thermal disinfection. The cleaning device 126 can have at least onefinal rinse zone 156 which is subdivided, for example, into a pump finalrinse arrangement 158 and a fresh water final rinse arrangement 160. Forexample, a rinse nozzle system can be provided in the final rinse zone158 and 160, which rinse nozzle system can be fed with heated freshwater and/or with rinsing fluid from a rinse tank. The pump final rinsearrangement 158 can be configured to carry out at least one final rinsecycle in a recirculation method using at least one final rinse liquid.In the fresh water final rinse arrangement 160, fresh water, which canoptionally be heated and/or admixed with a final rinse aid, inparticular as a so-called final rinse solution, can be applied to theitems 143 to be cleaned by means of the application device 130 andtherefore final residues of soiling and residues of the cleaning fluidare rinsed off from the items 143 to be cleaned. The cleaning device 126can further have one or more neutral zones 162 in which no cleaningtakes place. After passing through the cleaning zones 150, the items 143to be cleaned can then enter at least one drying zone 164 in which hotair can be applied to the items 143 to be cleaned for example by meansof a fan in order to accelerate drying of the items 143 to be cleaned.

Determining hygiene value shares from the influencing variables using aprespecified relationship between each influencing variable and therespective hygiene value share 120 of said influencing variable andadding up previously achieved hygiene value shares can take place atdifferent times during the transportation of the items 143 to be cleanedthrough the cleaning chamber 128. A time axis t with time units is shownin FIG. 2. Exemplary times at which determining of hygiene value shares120 and adding up of the determined hygiene value shares can take placeare identified in FIG. 2 as arrows with reference numeral 166. Inparticular, display of the previously achieved hygiene values can takeplace at these times 166, for example on a display device 168, inparticular a display, of the controller 118. The determining device 136is configured to determine hygiene value shares from the influencingvariables using the prespecified relationship between each influencingvariable and the respective hygiene value share of said influencingvariable. For recording the influencing variable, the cleaning device126 has at least two measuring devices 134, not illustrated in FIG. 2,which are configured to detect at least one influencing variable in atime-resolved manner. The measuring devices 134 can comprise at leasttwo sensors selected from the group consisting of: at least onetemperature sensor for recording at least one temperature of the atleast one cleaning fluid; at least one mechanical or fluidic sensor forrecording at least one measurement variable of a mechanical action ofthe at least one cleaning fluid on the items 143 to be cleaned, inparticular at least one pressure sensor for recording at least onepressure of the at least one cleaning fluid and/or at least one flowsensor for recording at least one flow of the at least one cleaningfluid; at least one concentration sensor for recording at least oneconcentration of at least one disinfectant in the at least one cleaningfluid; at least one concentration sensor for recording at least oneconcentration of at least one detergent concentrate in the at least onecleaning fluid; at least one pH sensor for recording at least one pHvalue of the at least one cleaning fluid.

At times 166, the expected actual hygiene value can be compared with thedesired hygiene value and influencing of at least one influencingvariable can take place if the desired hygiene value is undershot. Forexample, a duration of the cleaning and/or a mechanical effect and/or aneffect of the final rinse arrangement and/or a concentration and/ormetering and/or at least one pH value and/or the temperature of the atleast one cleaning fluid can be increased in at least one cleaning zonethat follows in the transportation direction.

The cleaning device 126 can be configured to carry out at least onechecking step. The checking step can be carried out until the items 143to be cleaned are located within a last cleaning zone, for example thefinal rinse zone 156, in particular the fresh water final rinse zone160, in a transportation direction. For example, the checking step cantake place at a time identified by arrow and reference numeral 168.During the checking step, the expected actual hygiene value can onceagain be compared with the desired hygiene value and at least one safetymeasure can be taken when the desired hygiene value is undershot. Thesafety measure can comprise at least one measure selected from the groupconsisting of: the transportation device 145 is stopped; thetransportation device 145 is slowed down; a pressure of the cleaningfluid in the application device 130 of the last cleaning zone 160 isincreased; a flow rate of the cleaning fluid in the application device130 of the last cleaning zone 160 is increased.

FIG. 3 shows a comparison of the achieved hygiene value shares persecond according to A0 methods (identified by reference numeral 170),according to HUE methods (identified by reference numeral 172) andaccording to the SUE method (identified by reference numeral 174) for aconcentration (2.5 ml/l surfactant+2.5 ml/l potassium hydroxide). TheHUE value per second is plotted from 0 to 400 on the left-hand-side Yaxis and the A0 value per second is plotted from 0 to 50 on a firstright-hand-side Y axis and the SUE per second is plotted from 0 to 10 ona second right-hand-side Y axis. All curves show a high temperaturedependency. However, A0 methods and HUE methods do not take into accountthe influence of the concentration or composition of the at least oneadditive of the cleaning fluid on the hygiene effect. For example, hightemperatures may be required in order to achieve a hygiene levelprespecified according to A0 or HUE methods. The SUE method can allowthe concentration or composition of the at least one additive of thecleaning fluid on the hygiene effect to be taken into account andtherefore render possible operation of the cleaning device at lowtemperatures with the hygiene effect remaining the same.

FIG. 4 shows a prespecified relationship between the influencingvariable temperature T in ° C., the hygiene value share of saidinfluencing variable according to the SUE method and the concentration.Curve 176 shows the influence of the temperature for a concentration of(2.5 ml/l surfactant+2.5 ml/l potassium hydroxide). Curve 178 shows theinfluence of the temperature for a concentration of (5 ml/l surfactant+5ml/l potassium hydroxide). Curve 180 shows the influence of thetemperature for a concentration of (7.5 ml/l surfactant+7.5 ml/lpotassium hydroxide). Curve 182 shows the influence of the temperaturefor a concentration of (10 ml/l surfactant+10 ml/l potassium hydroxide).By increasing the concentration, a higher hygienization value share canbe achieved with the temperature remaining the same. An increase in theconcentration can therefore compensate for a drop in temperature.

While exemplary embodiments have been disclosed hereinabove, the presentinvention is not limited to the disclosed embodiments. Instead, thisapplication is intended to cover any variations, uses, or adaptations ofthis disclosure using its general principles. Further, this applicationis intended to cover such departures from the present disclosure as comewithin known or customary practice in the art to which this inventionpertains and which fall within the limits of the appended claims.

LIST OF REFERENCE SYMBOLS

-   110 Prespecifying a desired hygiene value which is to be achieved    with the cleaning-   112 Time-resolved recording of at least two influencing variables-   114 Determining hygiene value shares from the influencing variables-   116 Calibration-   118 Controller-   120 Ascertaining an expected actual hygiene value at the end of the    cleaning from the hygiene value shares-   122 Comparing the expected actual hygiene value with the desired    hygiene value-   124 Influencing at least one influencing variable-   126 Cleaning device-   128 Cleaning chamber-   130 Application device-   132 Data memory-   134 Measuring devices-   136 Determining device-   138 Evaluating device-   140 Comparing device-   142 Influencing device-   143 Items to be cleaned-   144 Transportation device-   145 Transportation direction-   146 Inlet-   148 Outlet-   149 Drive-   150 Cleaning zones-   152 Wash tank-   154 Thermal disinfection zone-   156 Final rinse zone-   158 Pump final rinse arrangement-   160 Fresh water final rinse arrangement-   162 Neutral zones-   164 Drying zone-   166 Time-   168 Time-   170 Hygiene value shares per second according to A0 methods-   172 Hygiene value shares per second according to HUE methods-   174 Hygiene value shares per second according to SUE methods-   176 Curve-   178 Curve-   180 Curve-   182 Curve

What is claimed is:
 1. A method for cleaning items to be cleaned, comprising: (a) using a cleaning device having at least one cleaning chamber and at least one applicator for applying at least one cleaning fluid to the items to be cleaned in the cleaning chamber; (b) prespecifying a desired hygiene value; (c) time-resolved recording of at least two influencing variables which influence hygienization of the items to be cleaned; (d) determining hygiene value shares from the influencing variables using a prespecified relationship between each influencing variable and the respective hygiene value share of said influencing variable; (e) ascertaining an expected actual hygiene value at the end of the cleaning from the hygiene value shares; (f) comparing the expected actual hygiene value with the desired hygiene value; and (g) changing at least one of the influencing variables based on the comparison.
 2. The method as claimed in claim 1, wherein step (f) further comprises identifying whether the expected actual hygiene value is lower than the desired hygiene value.
 3. The method as claimed in claim 1, wherein the desired hygiene value is selected from the group consisting of: an A0 value according to DIN EN ISO 15883; a hygiene level to be achieved according to DIN 10510, at the desired prespecifications for tank and boiler temperatures according to DIN 10510; a number of HUE units according to the NSF3 standard; a reduction in a population of a target germ.
 4. The method as claimed in claim 3, wherein the desired hygiene value is a reduction in a population of a target germ which is to be achieved overall with the cleaning, wherein the reduction is a reduction in the population of Staphylococcus aureus.
 5. The method as claimed in claim 1, wherein the influencing variables are selected from the group consisting of: a duration of the cleaning; at least one temperature of the at least one cleaning fluid; at least one measurement variable which is characteristic of a mechanical action of the at least one cleaning fluid on the items to be cleaned; at least one concentration of at least one disinfectant in the at least one cleaning fluid; at least one concentration of at least one detergent concentrate in the at least one cleaning fluid; at least one pH value of the at least one cleaning fluid; at least one measurement variable which is characteristic of an effect of a final rinse operation.
 6. The method as claimed in claim 5, wherein the influencing variables is at least one measurement variable which is characteristic of a mechanical action of the at least one cleaning fluid on the items to be cleaned, wherein the measurement variable is one or both of a pressure or a flow rate of the at least one cleaning fluid.
 7. The method as claimed in claim 1, wherein the at least two influencing variables include the temperature of the at least one cleaning fluid.
 8. The method as claimed in claim 1, wherein the relationship between the influencing variables and the respective hygiene value shares of said influencing variables is prespecified by at least one of the following prespecifications: at least one calibration curve, wherein the calibration curve respectively indicates a relationship between the respective hygiene value share of the influencing variable and a further influencing variable, wherein the at least one further influencing variable is kept constant; at least one family of curves comprising a plurality of calibration curves, wherein the calibration curves each indicate a relationship between the respective hygiene value share of the influencing variable and a further influencing variable, wherein the at least one further influencing variable is kept constant within each calibration curve of the family of curves, wherein the at least one further influencing variable distinguishes between the calibration curves of the family of curves; at least one calibration table, wherein the calibration table respectively indicates a relationship between the respective hygiene value share of the influencing variable and a further influencing variable, wherein the at least one further influencing variable is kept constant; at least one family of calibration tables comprising a plurality of calibration tables, wherein the calibration tables each indicate a relationship between the respective hygiene value share of the influencing variable and a further influencing variable, wherein the at least one further influencing variable is kept constant within each calibration table of the family of tables, wherein the at least one further influencing variable distinguishes between the calibration tables of the family of tables.
 9. The method as claimed in claim 8, wherein the relationship between the influencing variables and the respective hygiene value shares of said influencing variables is prespecified by at least one calibration curve, wherein the calibration curve is at least one curve relating to a hygiene effect.
 10. The method as claimed in claim 1, wherein one or more of the duration of the cleaning is changed when it is identified during the comparison that the expected actual hygiene value differs from the desired hygiene value, or wherein at least one concentration of at least one additive in the at least one cleaning fluid is changed when it is identified that the expected actual hygiene value differs from the desired hygiene value, or wherein at least one mechanical application of the at least one cleaning fluid to the items to be cleaned is changed when it is identified during the comparison that the expected actual hygiene value differs from the desired hygiene value.
 11. The method as claimed in claim 10, wherein at least one measure for changing the intensity of the mechanical application is used, said measure being selected from the group consisting of: at least one pressure of the at least one cleaning fluid is changed; at least one flow rate of the at least one cleaning fluid is changed.
 12. The method as claimed in claim 1, wherein the items to be cleaned comprise a plurality of items to be cleaned, wherein each item is allocated a hygienization account in which previous hygienization units to which the item has been subjected are cumulatively stored.
 13. The method as claimed in claim 1, wherein the items to be cleaned are transported through the at least one cleaning chamber by a transporter that is subdivided into sections, each section being allocated a hygienization account in which previous hygienization units to which the items held in the respective section have been subjected are cumulatively stored.
 14. The method as claimed in claim 13, further comprising at least one checking step carried out until the items to be cleaned are located within the last cleaning zone in a transportation direction of the transportation device, wherein, during the at least one checking step, the expected actual hygiene value is again compared with the desired hygiene value, and wherein at least one safety measure is taken when the desired hygiene value is undershot.
 15. A cleaning device for cleaning items to be cleaned, comprising: at least one cleaning chamber and at least one applicator for applying at least one cleaning fluid to the items to be cleaned in the at least one cleaning chamber; at least two sensors for time-resolved recording of at least two influencing variables which have an influence on a hygienization of the items to be cleaned; and a controller having a data memory for storing a prespecification for a desired hygiene value to be achieved with the cleaning, the controller configured to: (i) determine hygiene value shares from the influencing variables using a prespecified relationship between each influencing variable and the respective hygiene value share of said influencing variable; (ii) ascertain an expected actual hygiene value at the end of the cleaning from the hygiene value shares; (iii) compare the expected actual hygiene value with the desired hygiene value; and (iv) change at least one of the influencing variables based on the comparison.
 16. The cleaning device as claimed in claim 15, wherein the controller is configured to determine whether the expected actual hygiene value is lower than the desired hygiene value.
 17. The cleaning device as claimed in claim 15, wherein the at least two sensors are selected from the group consisting of: at least one temperature sensor for recording at least one temperature of the at least one cleaning fluid; at least one mechanical or fluidic sensor for recording at least one measurement variable of a mechanical action of the at least one cleaning fluid on the items to be cleaned; at least one concentration sensor for recording at least one concentration of at least one disinfectant in the at least one cleaning fluid; at least one concentration sensor for recording at least one concentration of at least one detergent concentrate in the at least one cleaning fluid; at least one pH sensor for recording at least one pH value of the at least one cleaning fluid.
 18. The cleaning device as claimed in claim 15, wherein the cleaning device is selected from the group consisting of a conveyor washer and an automatic programmed washer.
 19. The cleaning device as claimed in claim 15, wherein the controller includes a data processor.
 20. The cleaning device as claimed in claim 15, wherein the two sensors are at least one mechanical or fluidic sensor for recording at least one measurement variable of a mechanical action of the at least one cleaning fluid on the items to be cleaned, wherein the mechanical or fluidic sensor is one or both of at least one pressure sensor for recording at least one pressure of the at least one cleaning fluid or at least one flow sensor for recording at least one flow of the at least one cleaning fluid. 